Apparatus for measuring impurities on wafer and method of measuring impurities on wafer

Abstract

Provided are an apparatus for measuring impurities on a wafer and a method of measuring impurities on a wafer. The apparatus includes: a wafer aligning device for aligning a wafer; a loading robot for moving and loading the aligned wafer; a rotation stage for rotating the loaded wafer; a scan robot for holding a natural oxide layer etching solution for the wafer and a metallic impurity recovery solution; and a container for receiving a predetermined etching solution and a recovery solution, wherein the scan robot removes an oxide layer on an edge region of the wafer.

What is claimed is: 
     
       1. A method of measuring impurities on a wafer, comprising:
 aligning a wafer and then loading the wafer on a rotation stage by a loading robot; 
 removing an oxide layer on an edge region of the wafer by using an etching solution; 
 collecting metallic impurities on a surface of the wafer edge region having the oxide layer removed, by using a recovery solution; and 
 analyzing the metallic impurities by using the extracted recovery solution, 
 wherein the collecting of the metallic impurities on the surface of the wafer edge region having the oxide layer removed comprises:
 holding a recovery solution by a tube disposed at a bottom end of a scan robot; 
 lowering the scan robot down to dispose a cut region in the bottom end of the tube on the lateral side of the wafer edge region and contacting the recovery solution, held in the cut region of the tube, to the wafer edge region; and 
 extracting the metallic impurities on the wafer edge region while rotating the rotation stage of the wafer. 
 
 
     
     
       2. The method according to  claim 1 , wherein the removing of the oxide layer on the wafer edge region comprises:
 holding the etching solution by the tube of the scan robot; 
 lowering the scan robot down to dispose the cut region of the tube on the lateral side of the wafer edge region and contact the etching solution held the cut region of the tube with the wafer edge region; and 
 etching the oxide layer on the wafer edge region while rotating the rotation stage having the wafer mounted. 
 
     
     
       3. The method according to  claim 1 , wherein an amount (V1) of the etching solution that the scan robot collects and holds is about 100 μL≦V1≦about 1000 μL. 
     
     
       4. The method according to  claim 1 , wherein an amount (V2) of the recovery solution that the scan robot collects and holds is about 100 μL≦V2≦about 1000 μL. 
     
     
       5. The method according to  claim 1 , wherein the recovery solution is a mixed solution of hydrofluoric acid and hydrogen peroxide. 
     
     
       6. The method according to  claim 5 , wherein the recovery solution has the chemical composition of X % HFY % H2O2 (0.1≦X≦5, 1≦Y≦28).